DISTRICT HEATING/HEAT NETWORKS


BRIDGING THE GAP BETWEEN DISTRIC


For large heat network projects, it’s at the design stage that


viability – or a lack of – becomes clear. Here, Franz Huelle, head of technical at REHAU Water Technologies, looks at how to bridge this feasibility gap and what options exist for design teams


Traditional district heating tools, CAD packages and calculations completed with spreadsheets can be limited when it comes to combining different pipe systems, working with complex material data or seeing a scheme feasibility to a design that’s ready to be implemented. What these traditional tools aren’t able to provide is joined-up support for the technical decisions needed at each stage.


BRIDGING THE GAP A more advanced set of digital functions and outputs can bridge the gap by bringing hydraulics, performance, multiple material combinations and installation into one workspace. Hydraulic design is not just sizing pipe but considering current and future use of the system, its dynamic and peak use. It must take into account radial, ring and meshed networks, how heat sources are set up, number of users and location, as well as plans for the future with reserve capacity. When current and future demand can be properly estimated, plant and pipe sizing can be optimised correctly and energy use can be made more efficient, with costs kept to a minimum without impacting system performance. A similar principle is in play for material choices.


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t can be incredibly frustrating when plans stall due to lack of software robustness, where the


complexity of design from concept to delivery is not achieved. Designs begin with sound concepts, but can unravel when put through the paces of hydraulics, pipe sizing, routing and installation practicality. This is without mentioning costs, which add pressure on every project. Part of the reason the design stage has this


‘make or break’ element to it is that, at the initial concept stage before designs begin, there is software to do much of the checking needed to ensure feasibility. Similarly, once designs have been finalised, there are software tools for optimising the system. This leaves a significant gap between the two, where many designs fall through.


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THE FEASIBILITY GAP The feasibility gap is a concern as district heating projects are not just becoming more common, but more complex. As frequency and complexity of projects increases, so too does the pressure on consultants and engineers to ensure plans have a high level of precision and practicality. The Heat Network Technical Assurance Scheme (HNTAS) TS1, which is expected to be phased in from 2027, raises the bar when it comes to design requirements, installation and operation. Designers will need to provide evidence to justify pipe sizing, heat loss calculations, routing decisions and general installation feasibility. The tools used for this part of the process must support the level of detail needed. In short, these are all areas where software and technical support could be invaluable.


ENERGY & SUSTAINABILITY SOLUTIONS - Summer 2026


Steel is a traditional choice, but with advances in polymer such as larger diameter systems it is no longer the go to. In addition, steel brings added complexities such as the need for specialist welding, increased need for custom parts and thermal expansion compensation. Other viable materials, such as the polymers PP-R and PE-Xa, can remove the requirement for expansion loops and leak detection systems. Other advantages include: the ability to use long continuous coil lengths (up to 570m), material flexibility and the reliability of connections. In reality, many projects are best served by a


carefully considered combination of materials, rather than using only one. Software created to include multiple materials, sizes and both UNO and DUO for such use cases can help designers make materials decisions confidently and quickly.


www.essmag.co.uk


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